This lesson will provide students with an introduction to the mole, introduce them to a working definition of a mole, and show them what we use the mole for, thus identifying it's importance. These topics are of absolute importance to be successful in any chemical field. Because molecules and atoms are counted as moles but measured through mass, a chemist must know how to do this. If not understood, the chemist would just be doing blind reactions and could not only be wasting material but also be putting him/herself at risk. A general knowledge of these topics must be obtained to successfully be able to convert amongst the appropriate units
Objectives
Students will be able to
1) Use molar masses (grams/mol) to convert between # of moles and the mass of a substance
2) Provide an understanding of Avogadro’s number (6.022x10E23) by converting amongst masses, volumes, and # of atoms/particles by using conversion factors and defining Avogadro's number in their own terms
3) Define a mole in their own words and identify the number of particles in a mole as 6.022x10E23
Do Now: This will be relevant to the previous days lesson. It is multi-purposeful. It will get the students working on something in the beginning of the class to help them settle down and get ready for the day's work/lesson. It can also be used as a small formative assessment to see how well they retained the information from yesterday. The Do Now for this lesson will require them to identify a list of units as measures of volume, mass, quantity, etc. There may not necessarily be only one answer for each type of unit. These are the units I will use along with the desired answers:
A dozen = quantity
A gallon = volume
A meter = distance/length
A gram = mass
A bushel = volume
A liter = volume
A kilometer = distance/length
A minute = time
A ream of paper = quantity
I will introduce Avogadro’s Number with an explanation of Avogadro’s number being a set number (6.022x10²³) of atoms or molecules and how a mole of one element can have a greater mass than a mole of another element. An explanation of an elements molar mass (the mass of one mole of a substance in grams per mole) will be necessary. I will use analogies to make comparisons (e.g. a dozen tennis balls). I will ask students for other examples of this type expecting answers such as a ream of paper. Students will most likely make the mistake of mentioning a herd of sheep or a gallon of milk. Hopefully this will occur, it will be a good opportunity to elaborate on the fact that a mole is a set number of atoms or molecules of a substance whereas a herd of sheep is not defined as a specific amount and a gallon of milk is a measure of volume not a measure of quantity. After explaining what it is, I will ask them why they think it may be important. Hopefully, after having completed the paper clip activity from a few days earlier, they will point out that it could be useful for counting atoms and they may even point out that it would be useful for conversions. With the paper clip activity fresh in their heads, prior knowledge should not be hard to activate. They should be able to understand that different elements will have different atomic masses, therefore a mole of different elements will have different masses. I will tell them that at the end of the lesson they should be able to tell me how many moles of a substance are present if I give them a particular mass of that substance.
Instructional Activities
The students need to understand why the mole is so important. I will have them take out their notebooks and start copying down what I do on the board. I will begin telling them that when chemists do chemical reactions, it is more convenient for them to work with moles than with mass because chemical reactions don't recognize masses when they are reacting. Chemical reactions work in terms of moles. In other words, when a chemical reaction takes place it is a certain number of molecules that react, not a certain mass of molecules. I will tell them that for chemists to figure out how many moles of a substance they have they need to first weigh it. They then need to convert that number to moles through a conversion factor. I will then setup a sample problem with a conversion factor and take them through the equation step by step by. I will label the equation with arrows to explain what each number represents and where it came from. I will work several samples on the board and let students ask questions about what I have done. Once I feel that the students have grasped the idea, I will hand out a worksheet of sample questions for them to do on their own. The worksheet will have two sections, one for individual work and one for the group work. After a predetermined allotment of time they will break up and work more problems in groups (assigned).
Concluding the Lesson
Ideally, the groups will be of four or five each (resulting in about 6 groups). Students will present answers up on the board with their group. The Students as a group will explain their logic behind setting up the problem and the class will vote on whether or not they think it is the right answer. I feel the benefits of these are two main reasons. The first is that I can use it as a brief assessment as described below. The second reason being that the students can get feedback from their peers about what they may have done wrong and on what they may have done well. Receiving feedback from peers in a class or group setting can seem much less negative than when it is coming from a teacher or some sort of authority figures mouth. I hope that they will respond more efficiently to feedback from a peer.
Assessing Student Understanding
As each group presents their answers on the board, I will use it as an assessment. This is a brief assessment that shouldn't take much time at all. As I observe the group up at the board I will take notes and observe things such as:
Who is doing the most talking?
Who is setting up the problem?
Who doesn't seem very interested in being up there?
Is it clear that one or two of the entire group solved all the problems?
These are clues that I can use to determine who may be getting the material and who may not be following it so much. I can then use this information to target specific types of examples for a particular student. Students will also have to hand the worksheet in. They will be allowed to take it home in case they were unable to finish it in class. I will give them two or three days to complete it in case they want to come in after school to work on it.
The reason I planned this lesson the way that I did was because I was in large part considering the assessment. I realize how valuable a teacher's time can be and I know that having a quick and effective assessment can be invaluable to moving the class along to the next topic. By having groups of students post answers on the board and have them explain their thought processes I can quickly determine who may be getting the hang of it and who may still be a little lost. The students in the group are grouped in a very particular way. I want the lower level achievers to be in the presence of the higher level achievers. It is my hope that the lower level students will pick something up from the higher level students as the higher level students discuss possible approaches to the problem. If the lower level achievers don't fully engage, it's OK. As I said before, this lesson is in large part planned around an assessment strategy. As the students are presenting, I essentially want the kids who are struggling to stick out to me like a sore thumb. To me they will stick out as kids who didn't participate, to others they will just be someone in the group who is shy or just isn't saying anything. It will be important to take note of which student(s) do the most talking during the explanation. This information will become very valuable to me because I can use it to pinpoint certain students and offer them the help that they may need to succeed with this particular topic. By giving the students the opportunity to work in groups they can ask each other questions that they may not want to ask the teacher for fear of embarrassment and give them the opportunity to learn from each other.
Title: Mole-Mass and Mole-Volume Relationships
Grade Level: 11
Course: General Chemistry
Lesson Overview
This lesson will provide students with an introduction to the mole, introduce them to a working definition of a mole, and show them what we use the mole for, thus identifying it's importance. These topics are of absolute importance to be successful in any chemical field. Because molecules and atoms are counted as moles but measured through mass, a chemist must know how to do this. If not understood, the chemist would just be doing blind reactions and could not only be wasting material but also be putting him/herself at risk. A general knowledge of these topics must be obtained to successfully be able to convert amongst the appropriate unitsObjectives
Students will be able to1) Use molar masses (grams/mol) to convert between # of moles and the mass of a substance
2) Provide an understanding of Avogadro’s number (6.022x10E23) by converting amongst masses, volumes, and # of atoms/particles by using conversion factors and defining Avogadro's number in their own terms
3) Define a mole in their own words and identify the number of particles in a mole as 6.022x10E23
Learning Performances
Steve Cannici - Learning Goal AnalysisMaterials Needed
CalculatorsTeacher made worksheet
Time Required
~90 MinutesInstructional Sequence
Introducing the lesson
Daily Agenda:Do Now: This will be relevant to the previous days lesson. It is multi-purposeful. It will get the students working on something in the beginning of the class to help them settle down and get ready for the day's work/lesson. It can also be used as a small formative assessment to see how well they retained the information from yesterday. The Do Now for this lesson will require them to identify a list of units as measures of volume, mass, quantity, etc. There may not necessarily be only one answer for each type of unit. These are the units I will use along with the desired answers:
A dozen = quantity
A gallon = volume
A meter = distance/length
A gram = mass
A bushel = volume
A liter = volume
A kilometer = distance/length
A minute = time
A ream of paper = quantity
I will introduce Avogadro’s Number with an explanation of Avogadro’s number being a set number (6.022x10²³) of atoms or molecules and how a mole of one element can have a greater mass than a mole of another element. An explanation of an elements molar mass (the mass of one mole of a substance in grams per mole) will be necessary. I will use analogies to make comparisons (e.g. a dozen tennis balls). I will ask students for other examples of this type expecting answers such as a ream of paper. Students will most likely make the mistake of mentioning a herd of sheep or a gallon of milk. Hopefully this will occur, it will be a good opportunity to elaborate on the fact that a mole is a set number of atoms or molecules of a substance whereas a herd of sheep is not defined as a specific amount and a gallon of milk is a measure of volume not a measure of quantity. After explaining what it is, I will ask them why they think it may be important. Hopefully, after having completed the paper clip activity from a few days earlier, they will point out that it could be useful for counting atoms and they may even point out that it would be useful for conversions. With the paper clip activity fresh in their heads, prior knowledge should not be hard to activate. They should be able to understand that different elements will have different atomic masses, therefore a mole of different elements will have different masses. I will tell them that at the end of the lesson they should be able to tell me how many moles of a substance are present if I give them a particular mass of that substance.
Instructional Activities
The students need to understand why the mole is so important. I will have them take out their notebooks and start copying down what I do on the board. I will begin telling them that when chemists do chemical reactions, it is more convenient for them to work with moles than with mass because chemical reactions don't recognize masses when they are reacting. Chemical reactions work in terms of moles. In other words, when a chemical reaction takes place it is a certain number of molecules that react, not a certain mass of molecules. I will tell them that for chemists to figure out how many moles of a substance they have they need to first weigh it. They then need to convert that number to moles through a conversion factor. I will then setup a sample problem with a conversion factor and take them through the equation step by step by. I will label the equation with arrows to explain what each number represents and where it came from. I will work several samples on the board and let students ask questions about what I have done. Once I feel that the students have grasped the idea, I will hand out a worksheet of sample questions for them to do on their own. The worksheet will have two sections, one for individual work and one for the group work. After a predetermined allotment of time they will break up and work more problems in groups (assigned).Concluding the Lesson
Ideally, the groups will be of four or five each (resulting in about 6 groups). Students will present answers up on the board with their group. The Students as a group will explain their logic behind setting up the problem and the class will vote on whether or not they think it is the right answer. I feel the benefits of these are two main reasons. The first is that I can use it as a brief assessment as described below. The second reason being that the students can get feedback from their peers about what they may have done wrong and on what they may have done well. Receiving feedback from peers in a class or group setting can seem much less negative than when it is coming from a teacher or some sort of authority figures mouth. I hope that they will respond more efficiently to feedback from a peer.Assessing Student Understanding
As each group presents their answers on the board, I will use it as an assessment. This is a brief assessment that shouldn't take much time at all. As I observe the group up at the board I will take notes and observe things such as:Who is doing the most talking?
Who is setting up the problem?
Who doesn't seem very interested in being up there?
Is it clear that one or two of the entire group solved all the problems?
These are clues that I can use to determine who may be getting the material and who may not be following it so much. I can then use this information to target specific types of examples for a particular student. Students will also have to hand the worksheet in. They will be allowed to take it home in case they were unable to finish it in class. I will give them two or three days to complete it in case they want to come in after school to work on it.
Teaching Resources
Rationale
The reason I planned this lesson the way that I did was because I was in large part considering the assessment. I realize how valuable a teacher's time can be and I know that having a quick and effective assessment can be invaluable to moving the class along to the next topic. By having groups of students post answers on the board and have them explain their thought processes I can quickly determine who may be getting the hang of it and who may still be a little lost. The students in the group are grouped in a very particular way. I want the lower level achievers to be in the presence of the higher level achievers. It is my hope that the lower level students will pick something up from the higher level students as the higher level students discuss possible approaches to the problem. If the lower level achievers don't fully engage, it's OK. As I said before, this lesson is in large part planned around an assessment strategy. As the students are presenting, I essentially want the kids who are struggling to stick out to me like a sore thumb. To me they will stick out as kids who didn't participate, to others they will just be someone in the group who is shy or just isn't saying anything. It will be important to take note of which student(s) do the most talking during the explanation. This information will become very valuable to me because I can use it to pinpoint certain students and offer them the help that they may need to succeed with this particular topic. By giving the students the opportunity to work in groups they can ask each other questions that they may not want to ask the teacher for fear of embarrassment and give them the opportunity to learn from each other.